Roddam Narasimha

Roddam Narasimha, known to his students as RN, was one of the most influential scientists in India and a world-renowned expert in fluid dynamics and aeronautical engineering. He died in Bangalore on 14 December 2020. He remained scientifically productive until a few weeks before he succumbed to a brain hemorrhage following an unrelated surgery. Those who met him knew him as a person of great depth and dignity. He left an enormous footprint on the scientific subjects and national projects on which he worked.

Born on 20 July 1933 in Bangalore, RN picked up his scientific interests and attitude from his father, who taught physics at the Central College in the city. RN thus naturally was drawn to physics. However, he got caught up in the heady days after India’s independence in 1947 and the fervor of nation building that ensued. In 1949 he decided to study mechanical engineering, rather than physics, at the Government Engineering College at Bangalore, and he graduated with distinction in 1953.

During an informal visit RN made to the Indian Institute of Science (IISc), the sight of a lovely World War II Spitfire standing in a quadrangle resulted in his decision to pursue a master’s degree in aeronautical engineering at the IISc. There he was mentored by Satish Dhawan, a stalwart in the country’s science and technology development. RN’s very first work, with Dhawan, on boundary-layer transition catapulted him to fame and continues to be cited and used today.

RN then went to Caltech for his PhD; Hans Liepmann, his adviser, remained a lasting influence on his scientific development. The year RN started his doctorate, 1957, was a turning point for US aerospace research because the Soviet Union launched Sputnik 1 that year. RN was impressed by the rapidity with which the US scientific establishment organized itself on both budgetary and academic fronts to start a space program. He was also quickly drawn into fundamental problems of free molecular flow and the structure of shock waves.

RN returned to the IISc as an assistant professor in 1962 and rose quickly through the ranks. He continued his exceptional research in rarefied gas dynamics, the transition to turbulence, and turbulent boundary layers. One of his abiding interests was relaminarization, which subsumes a host of mechanisms by which an initially turbulent flow can be rendered laminar. He built a first-rate fluid-dynamics research group, part of which in 1982 went on to create what is now the Centre for Atmospheric and Oceanic Sciences. Among his group’s achievements there were the novel laboratory simulation of clouds and their direct numerical simulations. RN conceived the Monsoon Trough Boundary Layer Experiment, carried out in the Indo-Gangetic Plain in 1990, to measure the atmospheric boundary-layer properties and derive flux relations relevant to monsoons. He conceptualized the Indo–French atmospheric research satellite Megha–Tropiques, launched in 2011 to study tropical clouds.

Amidst all that intellectual activity, RN served for 10 years as director of the National Aerospace Laboratories, where he focused on civil aviation, particularly trainer and light transport aircraft. He then spent about seven years as director of the National Institute of Advanced Studies, building a multidisciplinary research group of leaders from industry, academia, and government. He also created and chaired a new unit on engineering mechanics at the Jawaharlal Nehru Centre for Advanced Scientific Research. He never sought out leadership roles, although many came his way, including the presidency of the Indian Academy of Sciences; in each of his positions, he engaged in new initiatives that left the institutions better than they had been.

As a member of the Scientific Advisory Council to prime ministers Rajiv Gandhi and Manmohan Singh, RN was instrumental in establishing a major parallel computing initiative in the country and the Ministry of Earth Sciences. He served a critical role on the Indian Space Commission and was its longest-serving member.

RN was a highly cultured and scholarly person who combined the best from the East and the West and achieved an excellent balance between “building” and “doing.” Rather than advising his students to follow fashionable research areas, he taught them to work on questions that excited them and emphasized quality over quantity. He was well versed in Indic philosophy and scientific heritage; his awareness of the complexity of the country only enhanced his keen love for it. He was progressive on social issues and was free from prejudices against region, religion, gender, and age.

Many honors and recognitions came RN’s way, both in India and abroad. But he did not allow them to affect the personal qualities that endeared him to so many in the first place: his easy accessibility and openness to people of all walks of life; his intellect and his love for truth, scientific culture, and scholarship; his unprejudiced and disciplined advice; his clarity of thought in spoken and written words; his genuine curiosity; and the inspiration he provided to numerous younger colleagues. His legacy will remain far into the future.